Reviving Dark Pokémon...the vital role in Colosseum. Without this you cannot raise your Pokémon.

Each Dark Pokémon has a Bar showing Darkness instead of Experience. This is set out in Five Bars. When you have 2 Bars Cleared, you get one of the Missing attacks other than Dark Rush, When 3 you get another, When 4 are gone you get the 3rd...however when 5 are gone...nothing

To heal the Pokémon you need to do the following:

Keep it on your team

Use it when Battling

Call Out to it to get it out of 'Hyper State'

Massage it with the Cologne Case

Use Celebi to totally heal it (Can only be done twice in the entire game)

However once all 5 bars are empty, it is still a Dark Pokémon. How do you heal it without Celebi? here's a Step By Step guide.

Step 1: Go To The Celebi Shrine near Ageto Village

Step 2: Pick the Pokémon which has cleared it's Dark Meter (Hyper Pokémon cant be healed until they are no longer hyper)

Step 3: Your Pokémon's Darkness Will be gone

Step 4: Your Pokémon will now gain all the experience it got from battling whilst it was Dark

Step 5: If it goes by a certain level, you can evolve it or teach it new attacks, including the 4th one